8 Some Experiments in the Gold Bullion Assay, 



II. 



To shoiv the progress in parting: the surcharge at the 

 end of stated intervals between the time at which the red 

 fumes cease and the finish of the parting process. 



Thirty places prepared (Table B), each 10 grains of fine gold 

 (•99984), with 25 grains of fine silver. Copper and lead 

 case, as before. Cupelled for 21 minutes, flatted, annealed, 

 passed twice between rollers set at 8-lOOOths of an inch, 

 annealed, coiled, and placed in thimble tray. 



Boiled together in large beakers : — 



For 22 minutes in 45 ozs. 1st acid, by which time red 

 fumes off. 



For 15 minutes longer in 1st acid (one being removed per 

 minute). 



For 10 minutes in 35 ozs. 2nd acid (one being removed per 

 2 minutes). 



For 10 minutes in 35 ozs 3rd acid (one being removed per 

 minute). 



Each thimble, as it was removed, was washed in two 

 successive waters, afterwards all washed together before 

 annealing. 



The progress is rendered visible in the curve represented 

 in Diagram II. 



1 



